Roof insulation grants 2026 — Wallonia & Brussels
In 2026, the roof insulation grant reaches up to 70 €/m² in Wallonia (low-income households) and up to 50 €/m² via Renolution in Brussels. R-value conditions, eligible insulation types, attic access and the full procedure: we explain everything and handle the paperwork.
Indicative 2026 amounts, subject to income conditions and an R-value of R ≥ 4,5 (Wallonia) or R ≥ 4,0 (Brussels).
Roof insulation grant amounts by region and income category
Indicative 2026 amounts for non-converted or converted attics. In Wallonia, the grant is scaled to the cadastral income; in Brussels, the Renolution A/B/C categories correspond respectively to low, middle and high incomes. The minimum required R-value is shown in the last column.
| Income category | Wallonia Prime Habitation insulation | Brussels Renolution roof | Min. R-value eligibility condition |
|---|---|---|---|
| Low / precarious incomescat. I Wal. · cat. A Bxl | 50 – 70 €/m² | 40 – 50 €/m² | R ≥ 4,5 (Wal.) · R ≥ 4,0 (Bxl) |
| Middle incomescat. II Wal. · cat. B Bxl | 25 – 35 €/m² | 20 – 30 €/m² | R ≥ 4,5 (Wal.) · R ≥ 4,0 (Bxl) |
| High incomescat. III Wal. · cat. C Bxl | 10 – 20 €/m² | 10 – 20 €/m² | R ≥ 4,5 (Wal.) · R ≥ 4,0 (Bxl) |
| High R-value bonusR ≥ 6,0 — Renolution Bxl only | — | +5 – 10 €/m² extra | R ≥ 6,0 (Bxl only) |
Indicative amounts incl. VAT. Non-converted or converted attics, flat roofs and roof terraces are eligible under conditions. The general insulation grant also covers walls and floors. Request your quote for a precise calculation based on your situation.
The key criteria to maximise your roof grant
The final amount depends on several technical and administrative criteria. Here is what you need to know before planning your roofing work.
- R-value achieved
The minimum required R-value is R ≥ 4,5 in Wallonia and R ≥ 4,0 in Brussels. Reaching R ≥ 6,0 unlocks a Renolution bonus in Brussels. Our technicians size the insulation to exceed these thresholds.
- Insulation type
Blown cellulose, glass wool, rock wool, PIR or PUR panels are all eligible, provided that the R-value stated on the invoice matches the thickness actually installed. Blown cellulose is particularly well suited to hard-to-reach non-converted attics.
- Attic access
The attic configuration (non-converted, converted or inaccessible) determines the installation technique and the maximum achievable thickness. Inaccessible attics may require drilling for blown-in insulation, which is covered by the grant.
- Treated surface area
The grant is calculated per m² of insulated surface. A larger surface increases the total amount but does not change the unit rate. It is therefore advantageous to treat the entire surface in a single intervention.
- Prior energy audit
In Wallonia, a prior housing audit is mandatory for certain grant levels and can significantly increase the support obtained. In Brussels, the Renolution audit is strongly recommended. We work with partner accredited auditors.
Insulation guide → - Accredited contractor
The grants require a registered contractor (Wallonia) or a Renolution-approved one (Brussels) and a detailed invoice stating the R-value, thickness and insulation type. wendows is registered and meets these criteria in both regions.
The 2026 roof grant programmes in detail
Wallonia and Brussels-Capital each have their own programme. Here are the specific conditions for roof insulation in each region.
Prime Habitation — roof insulation
The Walloon Prime Habitation covers reinforcing roof insulation (non-converted attics, converted attics, flat roofs). The base amount is multiplied by a coefficient depending on the income category. A prior housing audit is recommended — and mandatory above a certain threshold — to maximise the amounts.
- Minimum thermal resistance R ≥ 4,5 for the roof (non-converted or converted attics)
- Contractor registered in Wallonia, detailed invoice with R-value and thickness
- Prior housing audit recommended (mandatory for the highest amounts)
- Combinable with the third-party payer scheme (no upfront funding)
- Processing time: 2 to 4 months after submission of the complete file
Renolution — roof insulation
The Renolution programme run by Brussels Environment subsidises roof insulation according to three income categories. Category A (low-income) benefits from the highest amounts. A bonus applies if the R-value reaches or exceeds 6,0. The building must predate 1996 for certain parts of the programme.
- Minimum R-value R ≥ 4,0 for the roof (bonus from R ≥ 6,0)
- Home over 10 years old, predating 1996 for certain Renolution components
- Renolution-approved contractor (official Brussels Environment list)
- Application submitted within 18 months after the final invoice
- Flat roofs and roof terraces eligible under specific conditions
We calculate, file and follow up your roof grant application
Eligibility check, quote net of grant, forms and technical certificates: you have nothing to handle.
- We check your rights
Region, income, age of the home, attic access and roof surface: we identify every grant you can claim before the quote is even drawn up.
- We quote net of grant
Your quote shows the estimated grant amount, the 6% VAT applied and the real remaining cost for your roof.
- We build the file
Wallonia or Renolution forms, compliant technical certificates, detailed invoice with R-value and thickness: we handle it all entirely after the works.
- We track the payment
We keep you informed of the steps and deadlines. If administrative additions are requested, we respond on your behalf.
Located in Flanders? The Mijn VerbouwPremie also covers roof insulation — ask us for the details for your municipality.
Estimate your roof insulation grant in seconds
Enter the surface of the roof to be insulated to get an indicative grant range. A free quote remains the only way to obtain a precise amount tailored to your situation.
Indicative estimate based on 50, 100 and 150 m². The actual amount depends on your income, the R-value achieved, the insulation type and the region.
90 m² blown-cellulose roof insulation — grant deducted
A concrete example to make the amounts tangible. Your project will be calculated based on your actual surface, your region and your income level.
Indicative example dated 2026, median incomes, Wallonia. Low-income households can obtain up to twice as much. Request your quote for a calculation tailored to your project.
Dig deeper into your roof insulation project
- Insulation grants (all types) Overview
Roof, walls and floor: all 2026 amounts by region, conditions and the full procedure to maximise your support.
See all grants → - Roof insulation price Costs & quotes
Price ranges by insulation type and surface, cost factors and a worked sample quote net of grants.
View the prices → - Insulation price All zones
Comparison of insulation costs by zone (roof, walls, floor), materials and installation techniques.
See the prices →
Your questions about roof insulation grants 2026
How much is the roof insulation grant in 2026?
In Wallonia, the Prime Habitation ranges from 10 to 70 €/m² depending on the income category (10–20 €/m² for high incomes, up to 70 €/m² for low incomes). In Brussels, Renolution offers from 10 to 50 €/m² across categories A, B and C. These amounts apply to non-converted and converted attics.
What minimum R-value must be reached for the roof grant?
In Wallonia, the required minimum R-value is R ≥ 4,5 for the roof. In Brussels (Renolution), R ≥ 4,0 is required, with a bonus if R ≥ 6,0 is reached. Our technicians systematically size the insulation to exceed these thresholds.
Which insulation types are eligible for the grants?
All common insulation materials are eligible: blown cellulose, glass wool, rock wool, PIR or PUR panels. The condition is that the R-value stated on the invoice matches the thickness actually installed, justified by the product datasheet.
Are inaccessible attics eligible for the grants?
Yes. Blown-in insulation in inaccessible attics (via drilling) is eligible for the grants, provided the blown thickness allows the required minimum R-value to be reached. The invoice must state the technique, thickness and R-value achieved.
Do I need an energy audit before applying for the roof grant?
In Wallonia, a prior housing audit is recommended and mandatory for the highest grant amounts. It can also reveal other combinable grants. In Brussels, the Renolution audit is strongly recommended. We work with partner accredited auditors.
Can the roof grant be combined with other support?
Yes. The roof grant can be combined with the wall grant, the floor grant, the 6% VAT (home over 10 years old) and, in Wallonia, with the third-party payer scheme that avoids upfront funding. You can also combine roof insulation with a solar panel installation to maximise savings.
Can wendows build the roof grant file on our behalf?
Yes, it is included in our service: eligibility check, quote net of grant, drafting of compliant technical certificates, submission of Wallonia or Renolution forms and follow-up through to payment. You have no administrative steps to take.
Your roof grant calculated, your file built
We check your rights, quote your roof insulation net of grant and submit the file: you only pay the real remaining cost.
- Free, no-obligation quote
- Grant & 6% VAT calculated and deducted
- Grant file built and tracked by wendows